Are you located in the United States? This hasn't been my experience. The closest I've had is the office manager determining that I would owe a co-pay or co-ins

Are you located in the United States? This hasn't been my experience. The closest I've had is the office manager determining that I would owe a co-pay or co-insurance and be asked to settle that day. It's always an option to decline and ask them to send you a bill in the mail, which usually does come a month later. What sort of service provider asked you to pre-pay?